This invention relates generally to the assembling of anti-friction bearing retainer rings and more particularly to bearing retainer rings fused together by welding.
There are two basic categories of ball bearing retainers, two piece assembled retainers and single piece wraparound retainers. A wraparound retainer is a single annular ring having a plurality of ball pockets for holding the bearing balls. Typically, the sides of the ball pockets extend outward into fingers which wrap around and retain the ball. A two piece retainer usually consists of two identical retainer halves, each half containing a plurality of ball pockets. The retainer halves are aligned with the ball pockets aligned with each other and then the two retainer halves are mechanically joined. One method of joining the retainer halves is riveting. Another is resistance welding or spot welding.
It is difficult to consistently obtain high quality resistance welds for the large quantities of mass produced bearing retainers. Two problems occur. The electric current used for resistance welding tends to follow the path of least resistance. This can result in melting in some area of the retainer other than the desired locations. This can cause arcing damage to the bearing raceway of the bearing ball surfaces. It is also possible for the current to be diffused to the extent that proper melting and welding do not occur. Multiple electrodes are typically used to weld the retainer halves together in a plurality of locations. If one electrode has a particularly low resistance path, it will tend to rob current from the other electrodes resulting in insufficient heating of the retainer in these other locations. Without sufficient heating, it is not possible to obtain an acceptable weld.
The second problem that can occur during resistance welding is due to wear of the electrodes. If the wearing is uneven, the current distribution among the electrodes will shift and not be uniform. Replacement of all the electrodes may be needed, even if only one is damaged or worn.
The foregoing illustrates limitations known to exist in present retainer ring welding methods. Thus, it is apparent that it would be advantageous to provide an alternative directed to overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter.